In order to keep existing buyers and to acquire new ones, quality plays an important role for every company. Buyers today, don't just expect a good product, they also need proof that the company can provide adequate certificates for their products or services. For now, only the ISO standard is the only standard recognized worldwide. In this article, I have analyzed quality assurance of JANAF Ltd. JANAF's main objective is to provide its clients with adequate quality for the receipt, storage and transport of the crude oil and petroleum products. JANAF can guarantee its quality with the following standards: ISO9000, ISO14000, OHSAS 18001 and ISO 50001.